The print engines used in laser printers, and in other printing devices such as photocopiers and facsimile machines that use laser printing technology, usually rely on a removable toner cartridge to supply the toner or printing medium used in the printing process. When the toner is exhausted from a particular toner cartridge, that cartridge is removed and replaced by another cartridge containing a fresh supply of toner. These toner cartridges typically have an opening in the shape of an elongated slot through which the toner is dispensed as the print engine operates, and that opening initally is sealed to prevent spillage of the toner during shipment and other handling of the toner cartridge. This seal must be removed when the toner cartridge is installed for use in a print engine, as is known to those skilled in the art.
Used toner cartridges frequently are recycled for muse. This recycling includes refining the cartridge with a fresh supply of toner. Because the toner itself is a fine powdery substance, most users of laser printers and similar apparatus choose not to refill their own used toner cartridges. Instead, used toner cartridges usually are refilled by others who make that activity their business, and who then ship the recycled toner cartridges to their customers for reuse. Because these recycled toner cartridges are handled and shipped after being refilled with toner, the toner-dispensing opening in each cartridge must be resealed to prevent spillage of the toner during shipment and handling. The preferred seal for resealing such toner cartridges is bonded or otherwise sealed to the cartridge so as to provide a fluid-tight seal in any attitude of the cartridge, but the seal should be readily removable by the user when the recycled cartridge is being installed in a print engine. Of significance from the viewpoint of those engaged in the business of recycling toner cartridges, the resealing process should take place in an expeditious manner so as to minimize that aspect of the cost associated with recycling the toner cartridges.